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This week, the National Institute of Transportation and Communities (NITC) at Portland State University released an enormous study looking at protected bike lanes in Washington D.C., Chicago, Austin, San Francisco, and Portland. The purpose of the study was to evaluate protected bike lanes to determine if they attract more cyclists, how well they are understood (e.g. no bike salmon here), if they improve perceptions of safety, how they are perceived by nearby residents, and how they are associated with economic activity. This is the first comprehensive study of its nature in the United States. This is important because our social norms around bikes are different here than they are in other countries, which affects many of the questions addressed in the study.

The study utilized 204 hours of video footage, which depicts the patterns and activities of 16,393 cyclists and 19,724 motorists at intersections. Intersections are an important focal point, because little is known about safety at intersections where the protected bike lane, well, goes away for a little bit. The study also included a survey of 2,283 local residents and 1,111 intercepted cyclists to better understand perceptions and experiences about the bike lanes. The survey and video provide a useful comparison between stated behavior (what people say they do, which we all know can have its issues) and actual behavior (i.e. what people actually do when they are driving or riding through intersections).

Anyhow, this is a significant study in terms of the size of the dataset and its implications for better understanding the behavior and reactions of cyclists and motorists alike to protected bike lanes. Suffice it to say that the study concludes that, yes, people feel safer in protected bike lanes and are more likely to use them. But that’s a very weak summary of a very strong study, so visit People for Bikes, Bicycle Retailer, Bike Portland, and Streetsblog, who have some more robust summaries of the key findings. Or read the study, at least the Executive Summary, here.

I’m a little late to the party in writing about the release of this study this week, but it did bring up an interesting question for me. First, let me be clear in stating that I think this is an important and significant study. Oh, and I’m a PhD student, so I’m kind of on board with this “science” stuff. But I want to address the question that is the title of this post. Do we need ‘Science’ to tell us about bike commuting?

This question came up when I noticed a post about the release of the study this week on Grist. The basic premise of that post is, duh. Yep, duh. Science went out and did this big study in order to determine the obvious. I’m only making “Science” a proper noun here since that’s how the author of the Grist post discussed the NITC study. The Grist article is kind enough to award the NITC study “Science’s coveted No Shit Award“. Right, those would be awarded to scientific studies that state the seemingly obvious.

Now, I must admit I am not surprised to hear this type of reaction to the results of this study. And Grist is known for their “gloom and doom with a sense of humor” approach. Ok, fine. But it still begs the question about whether or not we should bother conducting research to answer questions about bike commuting (ssssh, but I bet most of the authors at Grist would condone it).

Well, since I admitted earlier that I’m, you know, personally invested in the sciences, it should come as no surprise that I think that, yes, we should be conducting studies like the recent NITC study. We need a lot more of them, in fact. But it’s usually a good idea to justify why a study is needed (which, by the way, I’m sure the NITC researchers certainly did in order to get the funding for the study). But it’s easy to justify science to your scientific peers or to organizations that fund science. How about justifying it to those that are not invested in the sciences?

Just because we think something it obvious doesn’t mean it actually is. I think it was Oscar Wilde who said, “When you assume, you make an ass out of u and me.”

I did not read the whole NITC study, but it’s 147 pages in total. So I can assure you that there are some nuances to the general conclusion that protected bike lanes make us safer. The devil is in the details. But seriously, who has time for the details? See links earlier in post for handy summaries of key findings. And if you do have time for the details, I’m sure you’ll learn something beyond what you already think you know.

It sure is helpful to have a nice big dataset to take to policymakers and decision-makers that actually quantifies and documents (positive, in this case) information about bike commuting (even if bike commuters know it states the obvious).

Science can sway public opinion and lead to social change, especially science that manages leap out of the ivory tower and land in your latest bike blog post. Maybe it’s still preaching to the choir, but this thing blew up on the Internet this week, so at least it’s not just confined to academic audiences.

I am not a diehard lover of science. In fact, I study how science is used in decision-making, so I’m open to critically questioning science and its utility. Nevertheless, I would rather live in a world that has science than one that doesn’t (how’s that for an unscientific justification).

There are plenty of other reasons for doing more studies like the NITC study, but I’ll leave it at that for now. And I’m sure there are those of you that disagree with me. Let’s hear your thoughts. Because commenting on the Internet can actually work…

5 Responses to “Do We Need ‘Science’ to Tell Us About Bike Commuting?”

The importance of real, detailed logical and scientific arguments seems to be lost on most of the American public. Case in point: 97% of climate experts agree humans are causing global warming, but only 57% of Americans think the same thing.

Between the “research” of the toady pseudo-scientists of Big Oil, and a federal government immobilized by a radical right faction more interested in Big Oil job growth than the health of the planet, we will only see a change in attitude about environmentally friendly modes of transportation like bicycling when large numbers of people start dying because of air too filthy to breath and water too nasty to drink.

I feel you. One thing is that it’s hard to summarize a very broad-based 179-page study. Another thing is that the vast majority of Americans, including the vast majority of policymakers and maybe even most traffic engineers, have no idea what a protected bike lane is or why it’s better.

This study in particular was useful for:

1) Gathering well-refereed facts about exactly how much modern protected lanes increase biking in the American context, and in what ways.

2) Building the evidence needed to create the traffic models that predict how much a network of protected bike lanes would increase the capacity of a system.

3) Documenting the nuances of ordinary Americans’ feelings about this stuff.

4) Gathering the first-ever video data about how people use mixing zones in a protected bike lane context.

There are less than 200 miles of street in the entire country that have protected bike lanes on them. Changing that will require major institutions, like state DOTs, AASHTO, and so forth to build protected lanes into their toolkits. And though institutions are influenced by intuition, they’re ultimately guided by data. That’s why I think this study is important.

Thanks for the link, Michael. I agree that the points made there are definitely not obvious and quite interesting! Data definitely has the power to guide decision-making, although numerous other factors can come into play, sometimes significantly more so, as well. But again, I’d prefer the data be there than not!

Indeed, and this study specifically looked at intersections! If you check out the link Michael provided above, it addresses your question. And well, the answer seems to be that it depends how the intersection is designed.